• International Journal of Precision Engineering and Manufacturing
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• 제4권2호
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• pp.57-63
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• 2003

A new method using a transfer function was proposed in the previous paper for analyzing motion errors of hydrostatic tables. The calculated motion errors by the new method, named as the transfer (unction method (TFM), were compared with the results by the conventional multi pad method, and the validity of the proposed method was theoretically verified. In this paper, the relationship between rail form error and motion errors of a hydrostatic table is examined theoretically in order to comprehand so-called 'the averaging effect of an oil film', and the characteristics of the motion errors in a hydrostatic table is tested. The tested hydrostatic table has three single-side pads in the vertical direction and three pairs of double-sides pads in the horizontal direction. The motion errors are tested for three rails which have different form errors. The experimental results are compared with the theoretical results calculated by the TFM, and both results show good agreement. From the results, it is shown that the TFM is very effective to analyze the motion errors of hydrostatic tables.

• Industrial Engineering and Management Systems
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• 제13권2호
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• pp.231-249
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• 2014

This paper discusses a green supply chain with a manufacturer and a collection trader, and it proposes an optimal production planning for remanufacturing of parts in used products with quality classification errors made by the collection trader. When a manufacturer accepts an order for parts from a retailer and procures used products from a collection trader, the collection trader might have some quality classification errors due to the lack of equipment or expert knowledge regarding quality classification. After procurement of used products, the manufacturer inspects if there are any classification errors. If errors are detected, the manufacturer reclassifies the misclassified (overestimated) used products at a cost. Accordingly, the manufacturer decides to remanufacture from the higher-quality used products based on a remanufacturing ratio or produce parts from new materials. This paper develops a mathematical model to find how quality classification errors affect the optimal decisions for a lower limit of procurement quality of used products and a remanufacturing ratio under the lower limit and the expected profit of the manufacturer. Numerical analysis investigates how quality of used products, the reclassification cost and the remanufacturing cost of used products affect the optimal production planning and the expected profit of a manufacturer.

• 대한간호학회지
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• 제40권2호
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• pp.172-181
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• 2010

Purpose: The purpose of this study was to examine the impact of strategies to promote reporting of errors on nurses' attitude to reporting errors, organizational culture related to patient safety, intention to report and reporting rate in hospital nurses. Methods: A nonequivalent control group non-synchronized design was used for this study. The program was developed and then administered to the experimental group for 12 weeks. Data were analyzed using descriptive analysis, $\chi^2$-test, t-test, and ANCOVA with the SPSS 12.0 program. Results: After the intervention, the experimental group showed significantly higher scores for nurses' attitude to reporting errors (experimental: 20.73 vs control: 20.52, F=5.483, p=.021) and reporting rate (experimental: 3.40 vs control: 1.33, F=1998.083, p<.001). There was no significant difference in some categories for organizational culture and intention to report. Conclusion: The study findings indicate that strategies that promote reporting of errors play an important role in producing positive attitudes to reporting errors and improving behavior of reporting. Further advanced strategies for reporting errors that can lead to improved patient safety should be developed and applied in a broad range of hospitals.

• 중환자간호학회지
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• 제14권3호
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• pp.62-72
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• 2021

Purpose : This study aimed to identify factors influencing clinical nurses' intention to report medication administration errors. Methods : This cross-sectional study collected data from 121 nurses in charge of administering medication at a university hospital in Korea using structured questionnaires. Data were analyzed using descriptive statistics, independent t-test, one-way ANOVA, Pearson's correlation coefficient, and multiple linear regression. Results : Participants' mean age was 26.90±3.99 years, and 89.3% were women. Their mean clinical career duration was 3.88±4.26 years. The average levels of patient safety culture, attitude toward reporting medication administration errors, and intention to report medication administration errors were 7.51 out of 10, 3.36 out of 5, and 4.85 out of 6, respectively. The multiple regression analysis results indicated that the statistically significant influencing factors were patient safety culture (𝛽=.21, p =.018) and attitude toward reporting medication administration errors (𝛽=.22, p =.015). Conclusion : To improve the intention to report medication administration errors among clinical nurses, a patient safety culture must be established, along with an education provision for improving their attitudes toward reporting such administration errors.

• Journal of Mechanical Science and Technology
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• 제17권6호
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• pp.825-835
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• 2003

Previous studies have demonstrated the importance of joint angle errors mainly due to skin artifact and measurement errors during gait analysis. Joint angle errors lead to unreliable kinematics and kinetic analyses in the investigation of human motion. The purpose of this paper is to present the Joint Averaging Coordinate System (JACS) method for human gait analysis. The JACS method is based on the concept of statistical data reduction of anatomically referenced marker data. Since markers are not attached to rigid bodies, different marker combinations lead to slightly different predictions of joint angles. These different combinations can be averaged in order to provide a "best" estimate of joint angle. Results of a gait analysis are presented using clinically meaningful terminology to provide better communication with clinical personal. In order to verify the developed JACS method, a simple three-dimensional knee joint contact model was developed, employing an absolute coordinate system without using any kinematics constraint in which thigh and shank segments can be derived independently. In the experimental data recovery, the separation and penetration distance of the knee joint is supposed to be zero during one gait cycle if there are no errors in the experimental data. Using the JACS method, the separation and penetration error was reduced compared to well-developed existing methods such as ACRS and Spoor & Veldpaus method. The separation and penetration distance ranged up to 15 mm and 12 mm using the Spoor & Veldpaus and ACRS method, respectively, compared to 9 mm using JACS method. Statistical methods like the JACS can be applied in conjunction with existing techniques that reduce systematic errors in marker location, leading to an improved assessment of human gait.

• 정보처리학회논문지B
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• 제18B권1호
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• pp.45-50
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• 2011

한국어 형태소 분석에서 미등록 형태소 오류들은 2가지 유형으로 나뉜다. 첫 번째 오류 유형은 형태소 분석기가 어떤 형태소열도 찾아내지 못하는 것이고, 두 번째 오류 유형은 등록 형태소들의 잘못된 조합을 찾아내는 것이다. 지금까지 대부분의 기존 미등록 형태소 추정 기술들은 단지 첫 번째 오류 유형에만 초점을 맞추어 왔다. 본 논문에서는 2가지 유형의 오류들의 모두 다룰 수 있는 미등록 형태소 추정 방법을 제안한다. 제안 방법은 SVM(Support Vector Machine)을 이용하여 미등록 형태소 오류들을 포함할 가능성이 있는 어절들을 검출한다. 그리고 CRFs(Conditional Random Fields)를 이용하여 검출된 어절들의 형태소 분리와 품사 태깅을 수행한다. 실험에서 제안 방법은 기능어 최장 일치 기반의 전형적인 방법보다 뛰어난 성능을 보였다. 실험 결과에 기초하여 미등록 형태소 오류의 두 번째 유형이 한국어 형태소 분석의 성능을 올리기 위해서 꼭 다루어져야 한다는 것을 알 수 있었다.

• 한국실천공학교육학회논문지
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• 제3권1호
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• pp.45-50
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• 2011

유한요소 해석(FEA: finite element analysis)의 발달로 복잡한 기계나 자동차 및 구조물에 대해서도 상세한 진동해석을 할 수 있게 되었다. 그러나, 복잡한 구조물을 정확하게 모형화하기 어렵고, 특히 접합부의 강성과 감쇠 특성을 알기 어렵고, 복잡한 형상을 단순화하는 과정에서 발생하는 오차 등의 이유로 유한요소해석 결과는 부정확할 수 있다. 반면에 실제 구조물의 실험 데이터로부터 추출한 실험적 모드해석(modal testing) 결과는 상세하지는 않지만 정확하다고 볼 수 있다. 그러나 실험 결과가 구조물의 진동 특성을 정확하게 나타낸다는 가정은 여러 가지 측정 오차로 인하여 정확하지 않을 수 있다. 이 논문에서는 실험적 모드해석의 기본이 되는 FRF(frequency response function; 주파수 응답함수)의 측정에 영향을 미치는 오차들을 측정 오차와 신호처리 오차로 구분하여 각각에 대해 세밀히 살펴보고, 그러한 오차들을 감소함으로써 보다 정확한 FRF를 구하는 방법에 대해서 고찰해보았다.

• 대한토목학회논문집
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• 제2권1호
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• pp.81-92
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• 1982

본(本) 연구(硏究)는 항공사진(航空寫眞)에 의한 3차원(次元) 좌표결정(座標決定)에 있어서 표정단계(標定段階)에서 야기(惹起)되는 오차(誤差)의 전파(傳播)를 고찰(考察)하므로써 위치결정(位置決定)에 미치는 영향(影響)을 이해(理解)하고저 하는데 목적(目的)을 두고 있다. 이에 본(本) 연구(硏究)에서는 사진상(寫眞上)의 상좌표(像座標)로부터 소요(所要) 절대좌표(絶對座標)를 해석(解析)하는데 필요(必要)한 표정(標定)을 전산처리(電算處理)하므로써 전파(傳播)되는 오차(誤差)를 비교(比較) 분석(分析)하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.1817-1827
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• 2009

Although human error is recognized as the primary cause of railway accidents and incidents, there have been limitations in finding the root causes of errors and developing effective corrective actions in the Korean railway industry, due to the absence of a systematic method and lack of professional knowledge and skills of investigators. Therefore, there has been a strong need for a systematic methodology for human error analysis. This paper introduces a methodology for analyzing human error m railway operations, called HEAR (Human Error Analysis and Reduction). HEAR is intended to help analysts identify the sequences and various levels of causes of operators' erroneous actions in railway accidents or incidents and make recommendations to eliminate or reduce the future possibility of similar errors and accidents. It was developed based on a thorough investigation of various techniques for human errors analysis and feedback from field investigators.

• International Journal of Precision Engineering and Manufacturing
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• 제2권2호
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• pp.73-80
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• 2001

The objective of this research is to develop a measurement error model for sculptured surface in On-Machine Measurement(OMM) process based on a closed-loop configuration. The geometric error model of each axis of a vertical CNC machining center is derived using a 4$\times$4 homogeneous transformation matrix. The ideal locations of a touch-type probe for the sculptured surface measurement are calculated from the parametric surface representation and X-, Y- directional geometric errors of the machine. Also the actual coordinates of the probe are calculated by considering the pre-travel variation of a probe and Z-directional geometric errors. Then, the step-by-sep measurement error analysis method is suggested based on a closed-loop configuration of the machining center including workpiece and probe errors. The simulation study shows the simplicity and effectiveness of the proposed error modeling strategy.